94 THE SCIENCE OF LOGIC 



speaking, it applies only to the action of non-free or necessitating 

 causes; these we call &quot;physical&quot; or &quot;natural&quot; causes in the 

 present context, as distinct from the free, self-determining activity 

 of the human will. The action of the former produces physical 

 uniformity, that of the latter only uniformity in the wider sense 

 moral uniformity. But it would be a mistake to imagine that 

 this looser and less reliable sort of uniformity, which characterizes 

 the phenomena dependent on human activity, is an insufficient 

 groundwork for scientific knowledge of these domains : the very 

 existence of the various social and economic sciences, their co 

 existence with human free-will, disproves any such assumption. 1 

 About the generalizations of the latter sciences we can, of course, 

 have only moral certitude, not physical ; and it is to non-free 

 causes, and to the law of physical uniformity, that we must mainly 

 direct our attention here. 



Is the law of uniformity, as understood to apply to the action 

 of non-free causes, an axiomatic, setf-evident, necessary, &quot; analytic &quot; 

 principle like the principle of causality, for example, that &quot; what 

 ever happens has a cause &quot; ? Or is it rather a derived, &quot; synthetic,&quot; 

 mediately evident truth, to which we assent only on grounds of 

 experience ? Some have held the former, some the latter view. 

 As a matter of fact the principle can be, and has been, interpreted 

 in two ways. Understood as a hypothetical judgment, it is a self- 

 evident, axiomatic truth ; regarded as categorical, it is a truth of 

 experience. 



The hypothetical judgment, &quot; If, or whenever, or wherever, 

 the same physical (non-free) cause acts in similar circumstances 

 (and therefore unimpeded, not interfered with by other causes), 

 it will always produce the same sort of effect,&quot; is an axiomatic, 

 analytic, self-evident judgment. For, as Father Joyce expresses 

 it, &quot; the very concept of a natural agent, devoid of free-will, in 

 volves that, under the same circumstances, its action will be of 

 the same kind &quot;. 2 It is a judgment whose truth the mind grasps 

 directly and intuitively from an adequate understanding of the 

 notions involved in it: &quot;physical, non-free cause,&quot; &quot;repeated 

 action unimpeded,&quot; &quot; similarity of effect &quot;. 



But the principle, thus stated, makes no categorical assertion 



1 Cf. MAKER, Psychology, 4th edition, pp. 423-4. Mr. JOSEPH (op. cit., t . 375) 

 seems to identify man s free actions, with capricious, motiveless actions, and to regard 

 them as, therefore, &quot; incalculable &quot;. But this is not an accurate conception of the 

 &quot; libertarian &quot; view of the will. C/. MAKER, op. cit. t pp. 396 sqq. 



9 Principles of Logic, p. 237. 



